• Toxicological Research
• /
• v.20 no.1
• /
• pp.71-82
• /
• 2004

Changes in cell cycle control in the lungs and liver of the B6C3F1 mice (20 males per each group) exposed to ozone (0.5 ppm), 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 1.0 mg/kg), and dibutyl phthalate (DBP, 5,000 ppm) after 52 weeks were examined through Western, Northern blot, and immunohistochemistry based on alterations in protein expression levels of G1/S checkpoints (cyclin D1, cyclin E, and PCNA), G2/M checkpoints (cyclin B1, cyclin G, and cyclin A), negative regulators (p53, p21, GADD45, and p27), and positive regulator (mdm2). Expression levels of cyclins D1, E, G, PCNA, mutant p53, and mdm2 proteins were higher in the lungs and livers treated with combination of toxicants than in those treated with ozone only. Expression levels of the wild-type and mutant p53, p21, GADD45, p27, and mdm2 proteins and mRNAs were higher in toxicant-treated groups than those of the control. Immunohistochemical analysis revealed staining intensities of the PCNA, cyclin D1, c-myc and mdm2 protein- treated lungs and livers were stronger than those of the control group. Our results showed that combined treatment of ozone with NNK/DBP altered the cell cycle control through instability of the wild-type p53 gene. Such pivotal p53-mediated cell cycle alterations may be responsible for the toxicity observed under our experimental condition. These results may be applied to risk assessment of mixture-induced toxicity.

• Journal of Korean Medicine for Obesity Research
• /
• v.21 no.1
• /
• pp.10-21
• /
• 2021

Objectives: Benign prostatic hyperplasia (BPH) is a progressive pathological condition characterized by excessive proliferation of the prostate. In this study, we evaluated the effect of Corni Fructus water extract (CF) on the promotion of prostate cell proliferation by dihydrotestosterone (DHT). Methods: The effect of CF on the proliferation of LNCaP prostate cells was evaluated, and DHT was treated to induce an in vitro BPH model. To study the mechanism of inhibition of cell proliferation and BPH by CF, changes in the expression of key factors related to cell cycle and BPH were investigated. We further investigated the effect on the production of reactive oxygen species (ROS) and nitric oxide (NO) to evaluate the antioxidant and anti-inflammatory efficacy of CF. Results: Inhibition of LNCaP cell proliferation by CF was associated with decreased expression of cyclin D1 and cyclin A and increased expression of cyclin-dependent kinase inhibitor p21. CF also suppressed expression of BPH inducing factors such as 5α-reductase type 2 and androgen receptor (AR) as well as prostate specific antigen (PSA). Furthermore, CF significantly blocked DHT-induced LNCaP cell proliferation and effectively attenuated DHT-induced expression of BPH mediators and cyclins. In addition, CF inhibited DHT-induced oxidative and inflammatory reactions by inhibiting production of ROS and NO. Conclusion: Our results demonstrated that CF probably acted as 5α-reductase type 2 inhibitor, preventing the 5α-reductase type 2-AR signaling pathway, thereby reducing the conversion of testosterone to DHT and the expression of PSA, which is at least correlated with the antioxidant and anti-inflammatory activities of CF.